The Most Common Disease Your Dog Probably Has
Periodontal disease is the single most prevalent health condition in domestic dogs. By the age of three, approximately 80 percent of dogs show some degree of periodontal disease. By middle age, it affects the vast majority of dogs to varying degrees. Despite this, it remains one of the most under-treated conditions in veterinary practice — partly because its early signs are subtle, and partly because owners often do not realise the extent of damage occurring below the gumline.
Understanding what periodontal disease is, how it progresses, and what can be done at each stage is genuinely one of the most impactful things a dog owner can learn. This is not a cosmetic issue. It is a systemic health concern with consequences that reach far beyond the mouth.
What Is Periodontal Disease?
The periodontium refers to all the structures that support the tooth: the gingiva (gums), the periodontal ligament that anchors the tooth in its socket, the cementum covering the root, and the alveolar bone forming the tooth socket. Periodontal disease is the umbrella term for inflammatory and infectious disease affecting these structures.
It begins with plaque — a soft, sticky film of bacteria that constantly forms on tooth surfaces. If not removed regularly, plaque mineralises into tartar (calculus) within days. Calculus provides a rough surface on which further plaque accumulates. As bacteria proliferate and migrate below the gumline, the body mounts an inflammatory response that, over time, destroys the very tissues it is attempting to protect.
The Four Stages of Periodontal Disease
Veterinary dentists classify periodontal disease into four stages, each reflecting increasing levels of tissue destruction:
Stage 1: Gingivitis
At this stage, inflammation is confined to the gingiva. The gums may appear slightly red or swollen at the margin, and there may be mild tartar accumulation. Crucially, at Stage 1, no bone or attachment loss has occurred. This is the only stage that is fully reversible with professional cleaning and diligent home care. The underlying bone and supporting structures are intact.
Stage 2: Early Periodontitis
Inflammation has progressed below the gumline and has begun to destroy the periodontal attachment. There is up to 25 percent attachment loss, detectable on dental radiographs. The dog may have noticeable tartar accumulation and gingival recession or pocket formation beginning around the affected teeth. At this stage, damage is occurring, but intervention can halt further progression.
Stage 3: Moderate Periodontitis
Attachment loss is between 25 and 50 percent. This represents significant destruction of bone and periodontal ligament. The affected teeth may appear mobile. Pockets around the teeth deepen, providing anaerobic environments where the most destructive bacterial species thrive. Treatment at this stage often involves more extensive procedures than simple scaling and polishing.
Stage 4: Advanced Periodontitis
Greater than 50 percent attachment loss has occurred. Teeth at this stage are often loose, painful, and non-salvageable. Extraction is typically the only appropriate treatment. Chronic infection at this level has almost certainly been seeding bacteria into the bloodstream on a regular basis.
Consequences Beyond the Mouth
The systemic consequences of untreated periodontal disease in dogs are increasingly well-documented in veterinary literature. Chronic oral infection is associated with:
- Bacteraemia: bacteria entering the bloodstream during chewing, tooth brushing, or dental procedures
- Endocarditis: bacterial colonisation of the heart valves, particularly the mitral valve
- Renal damage: chronic low-grade inflammation contributing to kidney disease over time
- Hepatic changes: inflammatory markers and altered liver enzyme patterns in dogs with severe periodontal disease
- Oronasal fistulas: in small breeds especially, bone loss around the upper canines can create an abnormal passage between the oral and nasal cavities
- Pathological jaw fracture: severe bone loss in small or toy breeds can weaken the mandible to the point of fracture during normal chewing
These consequences are not hypothetical. They represent real, documented outcomes in dogs whose dental disease was not adequately treated.
Which Dogs Are Most at Risk?
All dogs are susceptible to periodontal disease, but certain factors increase risk significantly. Small and toy breeds are disproportionately affected because their teeth are crowded into smaller jaws, creating areas where plaque accumulates and cleaning is difficult. Brachycephalic breeds — those with pushed-in faces such as Pugs, French Bulldogs, and Shih Tzus — often have teeth rotated or impacted due to skeletal anatomy, compounding the problem.
Genetics, diet, immune function, and the quality and consistency of home dental care all play meaningful roles. Dogs fed exclusively soft food may accumulate plaque more rapidly than those given appropriate dental chews or harder textures, though diet alone is not sufficient to prevent periodontal disease.
Professional Treatment at Each Stage
Professional treatment for periodontal disease always requires general anaesthesia. There is no safe or effective way to perform a thorough dental assessment and cleaning in a conscious dog. Under anaesthesia, a veterinary dentist or trained veterinary nurse will perform:
- Full-mouth dental radiographs to assess bone levels around every tooth
- Supragingival scaling to remove tartar above the gumline
- Subgingival scaling and root planing to remove deposits below the gumline and smooth root surfaces
- Pocket irrigation and, where appropriate, application of local antibiotic gels into deep pockets
- Polishing to smooth enamel surfaces and slow future plaque adherence
- Extraction of non-salvageable teeth
In Stage 3 and 4 cases, more advanced periodontal surgery, bone grafting, or guided tissue regeneration may be considered by specialist veterinary dentists, though extraction remains the most common outcome for severely affected teeth.
Home Care: The Only Thing That Changes the Trajectory
Professional dental cleaning, as important as it is, provides a clean starting point — not a long-term solution. Without consistent home care, plaque reaccumulates rapidly and the disease process resumes. Daily tooth brushing remains the gold standard for home dental care. A soft-bristled brush and toothpaste formulated for dogs — never human toothpaste, which contains compounds toxic to dogs — used consistently every day makes a measurable difference to plaque levels and gingival health.
Dogs introduced to brushing gradually, starting with simply touching the mouth and building up over several weeks, tolerate the process far better than those introduced abruptly. For dogs where brushing is genuinely not achievable, evidence-based alternatives include enzymatic oral gels, dental chews with the VOHC (Veterinary Oral Health Council) seal of acceptance, and certain water additives. These are adjuncts, however — none replaces brushing in terms of efficacy.